/Engine/Source/Runtime/ImageCore/Public/ImageCore.h
Copy Image, swapping RB, SrcImage must be BGRA8 or RGBA16. Sizes must match. Dest must already be allocated. Src == Dest is okay for in-place transpose.
namespace FImageCore { void FImageCore::CopyImageRGBABGRA ( const [FImageView](API\Runtime\ImageCore\FImageView) & SrcImage, const [FImageView](API\Runtime\ImageCore\FImageView) & DestImage ) }